Abstract

Plasma cell dyscrasias are a group of disorders that are characterized by clonal proliferation of plasma cells that produce clonal immunoglobulins. Localized proliferation of plasma cells is defined as plasmacytomas whereas systemic proliferation of plasma cells usually represents multiple myeloma (MM). Solitary Plasmacytomas (SP) are defined as single lesions in either bone or soft tissue that are biopsy-proven to have clonal plasma cell proliferation with no systemic involvement or end-organ damage attributable to the neoplasm. MM is defined as a clonal bone marrow proliferation >10% or an extramedullary plasmacytomas (EP) that is associated with end organ damage attributable to the neoplasm. This case represents a situation where a patient’s condition cannot be classified under International Myeloma Foundation Guidelines (IMFG) as this patient did not meet the guidelines for both EP and SP.  He did not have an SP because his single lesion in the lung had spread to lymph nodes and bone, and he did not have an EP because he did not have any bone marrow involvement or end-organ damage attributable to the plasma cell neoplasm. With no prior cases reported, it was decided that this patient would undergo a combination of radiation and systemic therapy. Although the patient did not have widespread systemic involvement or end-organ damage, it was decided to treat the patient with standard MM therapy to prevent any progression of the disease.